NREL Produces Ethylene via Photosynthesis
(National Renewable Energy Laboratory/Ethanol Producer Magazine) Scientists at the U.S. DOE’s National Renewable Energy Laboratory have demonstrated a better way to use photosynthesis to produce ethylene, a breakthrough that could change the way materials, chemicals, and transportation fuels are made, and help clean the air.
NREL scientists introduced a gene into a cyanobacterium and demonstrated that the organism remained stable through at least four generations, producing ethylene gas that could be easily captured. Research results were published in the journal Energy & Environmental Science.
The organism—Synechocystis sp. PCC 6803—produced ethylene at a high rate and is still being improved. The laboratory demonstrated rate of 170 milligrams of ethylene per liter per day is greater than the rates reported for the photosynthetic production by microorganisms of ethanol, butanol or other algae biofuels.
The process does not release carbon dioxide into the atmosphere. Conversely, the process recycles carbon dioxide, a greenhouse gas, since the organism utilizes the gas as part of its metabolic cycle.
…“Our peak productivity is higher than a number of other technologies, including ethanol, butanol, and isoprene,” (NREL principal investigator, Jianping) Yu said. “We overcame problems encountered by past researchers. Our process doesn’t produce toxins such as cyanide and it is more stable than past efforts. And it isn’t going to be a food buffet for other organisms.”
After the culture reaches maximum growth, it’s possible that it could keep producing for months at a time, said Rich Bolin, who is a member of NREL’s partnerships group. The ethylene gas it produces naturally leaves the organism, spurring the organism to keep producing more.
The ethylene would be produced in an enclosed photobioreactor containing seawater enriched with nitrogen and phosphorous. READ MORE